Conventionally, patients having a deteriorated respiration function have been subjected to such a treatment as performing a tracheostomy and inserting a tracheostomy tube into the incision site. As a result, air can be sent directly to the lungs through a trachea from the outside, not through a throat or a nose, or can be sent to the outside through the trachea from the lungs (for example, see Patent Document 1, as discussed below). In such a tracheostomy tube, a connector section is provided at the base end portion of a lumen body in which an airway securing lumen is formed from the base end portion to the tip end portion and a cuff which is expandable and contractible is provided on the outer circumference of the tip end portion of the lumen body.
A cuff-expanding lumen allowing one side of the surface of the connector section to communicate with the inside of the cuff is formed in the wall of the lumen body and thus the cuff can be expanded by injecting air into the cuff through the cuff-expanding lumen from the connector section. The expanded cuff allows the tracheostomy tube to be supported by a predetermined portion of the trachea in a state that the trachea is clogged.
A suction lumen allowing the other side of the surface of the connector section to communicate with a predetermined portion of the surface of the lumen body is formed in the wall of the lumen body and thus sputum or the like accumulated between the lumen body and the trachea can be discharged externally through the suction lumen by allowing the connector section side to perform an suction. When the tracheostomy tube having the above-mentioned structure is attached to the incision site of a patient, a lubricant such as a jelly is applied to the surface of the lumen body or the cuff. As a result, the operations of attaching the tracheostomy tube to the incision site of a patient, and detaching the tracheostomy tube from the incision site when it should be replaced with the lapse of time after the attachment, can be performed smoothly.
Above mentioned Patent Document 1 is Japanese Unexamined Patent Application Publication No. 2003-93512.
However, in the tracheostomy tube described in Patent Document 1, there is a problem that the operation of applying a lubricant to the lumen body or the cuff is troublesome when the tracheostomy tube is attached to the trachea. Further, there is a problem in that sputum or foods can be easily accumulated inside the tracheostomy tube.
The present invention is contrived to solve the problems. It is an object of the present invention to provide a tracheostomy tube which can be smoothly attached to or detached from the incision site and in which sputum or the like is not easily accumulated therein.
In order to accomplish the above-mentioned object, according to an aspect of the present invention, there is provided a tracheostomy tube comprising: a lumen body having an airway securing lumen extending from a base end portion to a tip end portion; a connector section formed at the base end portion of the lumen body; a cuff which is formed on the outer circumference of the tip end portion of the lumen body and which is expandable and contractible; a cuff-expanding lumen which is formed in the wall of the lumen body and which allows the surface portion of the connector section to communicate with the inside of the cuff; and a suction lumen which is formed in the wall of the lumen body and which allows the surface portion of the connector section to communicate with the surface portion of the lumen body, wherein a coating layer exhibiting surface lubricity in moisture is formed on the surface of the tracheostomy tube and the inner surface of the lumen body in which the airway securing lumen is formed.
In the tracheostomy tube having the above-mentioned structure, the coating layer exhibiting the surface lubricity in moisture is formed on the surface of the tracheostomy tube. As a result, when the tracheostomy tube is fitted to or detached from the incision site of a patient, it is possible to easily perform the operation of fitting or detachment by performing a simple operation such as dipping the surface of the tracheostomy tube into water. The coating layer exhibiting the surface lubricity in moisture is formed on the inner surface of the lumen body in which the airway securing lumen is formed.
As a result, when the inner surface of the lumen body gets wet by vapor or spit at the time of the patient's respiration, the surface lubricity is exhibited. Accordingly, sputum or the like is not easily attached to the inner surface of the lumen body. As a result, it is possible to prevent sputum or foods from being accumulated in the lumen body. In this case, the surface of the tracheostomy on which the coating layer is formed includes at least the surface of the lumen body or the cuff, that is, a portion coming in contact with the incision site of the patient when the tracheostomy tube is fitted or detached.
In the tracheostomy tube according an embodiment of to present invention, the coating layer may be made of a mixture of methylvinyl ether maleic anhydride copolymer and fluorine-containing acryl urethane silicon resin.
The mixture exhibits the surface lubricity in moisture and thus allows the surface of the tracheostomy tube or the inner surface of the lumen body in which the airway securing lumen is formed to easily slide. Accordingly, since the insertion resistance when the tracheostomy tube is inserted into the incision site becomes small, the tracheostomy tube can be easily fitted. Similarly, the tracheostomy tube can be easily detached from the incision site and foreign substances such as sputum is not easily accumulated in the tracheostomy tube. The coating layer made of the mixture can be formed through a simple process such as dipping the constituent base members of the tracheostomy tube in the mixture, without performing any pretreatment such as introduction of a function group, thereby giving the lubricity to the constituent base members of the tracheostomy tube. Since the mixture is low in cost and is widely used, the mixture is easily available.
In the tracheostomy tube according to an embodiment of the present invention, the coating layer may be made of a mixture of methyl vinyl ether maleic anhydride copolymer and polyether-block-amide. Accordingly, the lubricity can be given to the constituent base members of the tracheostomy tube by the use of a simple process. The coating layer can be formed out of a material which is low in cost, is easily available, and is widely used. By using the mixture, it is possible to obtain the coating layer having high durability.
In the tracheostomy tube according an embodiment of to present invention, the coating layer may be made of a mixture including polyisocyanate and a mixture including polyvinyl pyrrolidone. Since the coating layer made of the mixtures can be formed on the surface of a constituent base member made of any polyurethane resin, it is possible to form the coating layer having excellent lubricity by making the constituent base members of the tracheostomy tube out of predetermined polyurethane resin.
In the tracheostomy tube according to the present invention, the coating layer may be formed by depositing a mixture including a solvent in which a material of the tracheostomy tube is poorly soluble. In this case, it is preferable that the main component of the solvent is alcohol such as 2-propanol or ethanol. As a result, it is possible to form the coating layer having excellent lubricity on the surface of the tracheostomy tube or the inner surface of the lumen body in which the airway securing lumen is formed, without melting the respective base members of the tracheostomy tube, specifically, the cuff.